The Sixth Extinction – Elizabeth Kolbert

Elizabeth Kolbert has in the 13 chapters of this book set out the irrefutable evidence for the role of humans in initiating a major extinction event. She shows that the impact of humans on other species is not limited to recent times, and that over long periods of time, many tens of thousands of years, humans have been responsible for the extinction of many large animals, from the destruction of Australia’s giant species around 40,000 years ago, to extinction of the giant birds of New Zealand, which were wiped out approximately 500 years ago. As she says in discussing the extinction of the American mastodon, “Its demise was part of a wave of disappearances that has come to be known as the megafauna extinction. This wave coincided with the spread of modern humans and, increasingly, is understood to be the result of it.” Today the pressure on the remaining large species including elephants and rhinos, not to mention tigers and other large predators, continues with poaching, logging, and the extension of human habitation into what was formerly wilderness areas, putting the survival of many species at risk.

She says that you can call this event the Holocene extinction, or the Anthropocene extinction, or the Sixth Extinction. In recent years, our understanding of the impact of climate change has focused our attention on increasing extinction rates, a phenomenon which affects all spaces, not merely large mammals. Elizabeth Kolbert graphically explains the problems associated with the acidification of seawater, and of rising temperatures, which is already having a devastating effect on coral reefs around the world. As she notes, “A study of more than eight hundred reef-building coral species, published in Science in 2008, found a third of them to be danger of extinction, largely result of rising ocean temperatures. This is made stony corals one of the most endangered groups on the planet: the proportion of coral species ranked as ‘threatened’, the study noted, ‘exceeds that of most terrestrial animal groups apart from amphibians’.”

However, she also explains that deforestation and climate change is already affecting many plants and insects, which are unable to adapt to rapidly changing conditions. In addition, she also highlights the problems of the human introduction of alien species, that is species introduced from other parts of the world, and the devastation which can result from this practice.

Elizabeth Kolbert is a journalist who readily engages with specialists, writes fluent English, and obviously believes that she has an important message for the reader, I strongly recommend this book, which anybody interested in the effect that humanity is having on our planet should read.